RSC Applied Polymers最新文献

This study focuses on the development of a novel seamless adhesive by investigating the interaction of N,N-dimethyl-p-toluidine (DMPT) in an acrylic-based polymer system. The optimal proportions of benzoyl peroxide (BPO) and DMPT were determined to achieve ideal curing time and fracture toughness, making the adhesive highly suitable for industrial applications. The prepared adhesive demonstrated a curing time that balances efficiency with performance, facilitating seamless splicing of artificial stone materials in production lines. The optimal curing time achieved was approximately 10 min at 25 °C, with a stress intensity factor (K) reaching up to 12.32 kPa m^1/2, demonstrating significant improvement in both efficiency and mechanical strength. Additionally, the ability to adjust the resin-to-powder ratio presents significant cost-saving opportunities for manufacturers. The adhesive exhibited remarkable color stability, with minimal changes observed even under elevated temperatures, resulting in nearly invisible splicing joints. These qualities, combined with strong bonding performance and aesthetic advantages, make the adhesive a promising candidate for use in bioelectronic devices, where durability, versatility, and optical clarity are essential. This research demonstrates the potential of advanced acrylic adhesives to enhance both traditional construction applications and emerging technologies in bioelectronics.

Materials that exhibit metallic luster without containing metals are promising alternatives to existing metallic paints and coatings. In this study, we successfully synthesized four types of anion-doped poly(3-alkoxyselenophene) and used them to develop metal-free metal-like lustrous films. By employing polyselenophene, we achieved the expression of luxurious glossy colors such as black and purple, which were difficult to obtain with previously reported polythiophene-based materials. The developed films were thoroughly investigated through reflectance spectroscopy, colorimetry, gloss measurements, and XRD analysis. The glossy colors exhibited by the polyselenophene films are suggested to arise from a well-balanced presence of face-on and edge-on lamellar crystals within the coated films, in addition to the optical properties of the polymer itself. The developed metal-like lustrous films do not contain any metals, being highly promising for applications in essential everyday items such as writing instruments, cosmetics, anti-counterfeiting inks, and automotive paints.

Imparting magnetic properties to elastomeric polymers opens up possibilities to generate intelligent materials that may mimic complex biological systems, allowing reversible deformations under a magnetic stimulus. Remotely triggered soft actuators made of thermoplastic polyurethane (TPU) and yttrium iron garnet, Y₃Fe₅O₁₂ (YIG), were prepared through micro melt compounding, a solvent-free and environmentally friendly scalable technique. The magnetic composites (mTPU) present a good interface between particles and the matrix while maintaining the elastomeric behaviour characteristic of TPU. Using a permanent magnet, the magnetomechanical behaviour of mTPU, with two different shapes and thicknesses, led to reversible bending at room temperature with a fast response time. Initial displacements at 100 Oe for a 500 μm thick tape and 85 Oe for a 150 μm thick tape are recorded. Thinner tapes enable more freedom in movement and have higher sensitivity to external magnetic fields, needing lower magnetic forces (around 38 times lower) for bending than the thicker tapes, that in turn allow for a more precise control. A switch actuator, composed of an mTPU/Au bi-layer, was developed to quickly open or close an electrical circuit upon exposure to a magnetic field.

The present study focuses on the synthesis and structural analysis of poly-ε-caproamide (PA6), produced through anionic polymerization of ε-caprolactam in bulk, utilizing mono and bifunctional activators. The research investigates the physical properties of PA6 synthesized under various polymerization conditions, aiming to understand how these conditions influence the polymer's behavior. The polymerization kinetics were monitored via dynamic rheology, offering insights into the progression of ε-caprolactam's conversion into PA6. Microstructural changes in the PA6 samples, including variations in the degree of crystallinity and the formation of α and γ crystalline structures, were systematically studied. These transformations were dependent on both the type and concentration of the activator used, as well as the specific polymerization parameters applied. The interplay between these factors significantly impacted the resulting chemical and physical structure of the PA6 samples. In the latter part of the study, hybrid composites were fabricated by reinforcing poly-ε-caproamide with two distinct types of fiber fabrics by reactive processing, achieving a 25% weight fraction of reinforcement. Scanning electron microscopy (SEM) revealed excellent interfacial adhesion between the fibers and the polymer matrix, confirming the effectiveness of the fabrication process and the potential of these composites for advanced material applications.

The biodegradation performance of non-pretreated and pretreated commercial polyesters was evaluated under simulated composting conditions to understand how abiotic pretreatment accelerates biotic degradation. Polylactic acid (PLA) and polycaprolactone (PCL) were subjected to hydrolysis pretreatment and assessed under simulated composting conditions for 120 days. In addition to tracking CO₂ evolution, polymer-intrinsic factors such as chain scission, measured by reductions in intrinsic viscosity molecular weight (M_η), and changes in crystallinity (X_c) were also evaluated for both non-pretreated and pretreated samples during the biodegradation process. Hydrolysis pretreatment resulted in a reduction of initial M_η and an increase of initial X_c for all polymer samples. The initial decrease in M_η was particularly marked for PLA, which showed about 30% decrease, while PCL exhibited a reduction of just around 7%. Regarding initial X_c, the most significant increase was also seen in PLA, which jumped from approximately 0% to c. 30%. Hydrolysis of semi-crystalline polymers primarily affects the amorphous region, where elevated temperatures allow water to break polymer chains easily. However, for PLA, the disruption of the crystalline structure leads to a less stable type of crystal, probably due to an increase in the rigid amorphous region that enhances the overall biodegradation process. The effect of pretreatment on the biotic phase showed minimal differences for PCL but a noticeable overall increase in biodegradation for the pretreated PLA.

Effective detection and monitoring of volatile amines are crucial for protecting human health and the environment, particularly in areas such as disease diagnosis and food spoilage detection. Traditional gas sensors, including electrochemical, semiconductor, and photochemical types, often suffer from limited selectivity, sensitivity and require complex and expensive synthesis and detection equipment. Colorimetric sensors, which are easily interpreted through visible colour changes, have recently gained attention for their simplicity and real-time detection capabilities. In this study, we present a chemosensing system based on the bindone motif, both as a small molecule (Bin) and embedded in a polymer backbone (PBin), for the effective colorimetric detection of volatile amines. Our system exhibits high selectivity and sensitivity, with detection limits as low as 0.04 ppm for Bin and 1.57 ppm for PBin. The colour change, driven by amine-induced tautomerisation, was confirmed through UV-Vis spectroscopy, NMR spectroscopy, and TD-DFT calculations. pH dependent studies reveal the importance of basicity on the mechanism and selectivity. By incorporating the bindone moiety into the polymer backbone, its thermal stability was significantly enhanced. The versatility of the sensor was demonstrated in solution, and paper-based film formats, with successful application in detecting amines released during fish spoilage. This work highlights the potential of the bindone-based chemosensor as a cost-effective, portable, and efficient tool for monitoring food freshness and other applications requiring the detection of volatile amines.

The viscosity of graphene-based conducting ink has been shown to significantly affect printed geometries, and it has been illustrated that it can be controlled by adjusting the crosslinking density. A porous substrate, such as a textile surface, has been selected for printing to emphasize the structure formation of nanofillers during cyclic bending. The graphene loading in the elastomer matrix was deliberately chosen beyond the percolation threshold to gain insight into the conducting network channels on the fabric substrate. Structure–property analysis revealed the formation of stable conducting geometries of graphene on textile yarns under cyclic stress. The processing parameters have been found to play a crucial role in fabricating a tightly packed, conducting ink-filled textile substrate, which reorganizes the structural integrity of the flexible film by application of stress. The flexibility of graphene flakes is found to be critical as it allows them to conform to the fabric's surface for enhanced wetting and to minimize the stress concentration. The composition of fabric materials plays an important role in enhancing adhesion with conducting layers, thus contributing to the overall resistance stability. Formulation and processing of graphene-based inks have been optimized to achieve consistent deposition of flexible conductive ink on textile surfaces capable of enduring bending stress, making it ideal for the next generation of wearable electronics applications.

Protective coatings are essential for shielding engineering materials from environmental and mechanical damage. A significant endeavor in this regard is detecting the damage in coatings and implementing necessary repairs. However, conventional detection methods often require specialized equipment and expertise, rendering them impractical for real-time monitoring. This work introduces an autonomous damage-reporting coating system based on a stress-responsive polymer network containing a Diels–Alder adduct mechanophore. When subjected to mechanical damage, the mechanophore undergoes a retro-Diels–Alder reaction, liberating a fluorescent π-extended anthracene moiety. The mechanically triggered “off-to-on” optical signal allows for highly sensitive detection of material damage preceding failure. A quantitative relationship between the extent of impact damage and the mechanochemically generated fluorescence is established, facilitating the prediction of material failure. Remarkably, the damage-reporting functionality is maintained even after incorporating pigments into the coating formulation, thereby broadening the applicability of this smart coating system in real-world scenarios.

Here, we report the copolymerization of a C20:1 monounsaturated long-chain α,ω (MULCH) diacid with polyamide-6,6 (PA66) and polyamide-6 (PA6), and subsequent post-polymerization derivatizations in the swollen or solid state. Surprisingly, most of the unsaturation survived harsh polymerization conditions. The partially unsaturated polyamides were subsequently derivatized through swollen- or solid-state chemistries, including epoxidation and thiol–ene click reactions, demonstrating the opportunity to transform a single nylon/MULCH copolymer into a plethora of high-performance specialty grades through processes like reactive extrusion or chemical washing. Bio-based MULCH diacids could thus serve as a foundation for bespoke polyamides; for example, enabling enhanced water resistance, crosslinkability, recyclability, or internal plasticization. The versatility afforded by MULCH diacid monomers adds significant value, supporting the growth of the bioeconomy. We illustrate these concepts with several examples of modifying MULCH copolymers: chemical staining, enhanced hydrophobicity through grafting of aliphatic pendants, crosslinking, and epoxidation. Chemical and physical properties are evaluated and compared to those of PA66 or PA6 homopolymer controls. Advances in vegetable oil processing and biotechnology have enabled the large-scale production of a variety of MULCH-diacids from lignocellulosic feedstocks. This work illustrates how the “bioadvantage” presented by monounsaturation can be exploited in high-value applications, facilitating the growth of the biobased chemical sector.

Hypercrosslinked polymers (HCPs) are a type of porous organic polymer that have been rapidly developed over the past few decades. These polymers are primarily synthesized through Friedel–Crafts alkylation over Lewis acid catalysts such as ferric chloride and aluminum chloride, leading to the formation of porous materials by cross-linking. HCPs can be prepared through strategies such as post-cross-linking of polystyrene-type polymer precursors, self-cross-linking of specific aromatic monomers, and cross-linking by external agents with aromatic monomers. Among these methods, the external cross-linking approach has been utilized in fields such as gas storage, adsorption, catalysis, separation, and energy storage due to its mild synthesis conditions, good stability, high yield, broad availability of monomers, and tunable structure. In this paper, recent research progress in the preparation of HCPs by external cross-linking methods, with a focus on the formation mechanisms, structural regulation, and applications, is reviewed. Additionally, the drawbacks and challenges while projecting future developments in HCPs are highlighted.